PCAP touchscreens with varying ITO dicing patterns

ABSTRACT

Embodiments include a method and system for projected capacitive (PCAP) touchscreen construction with laser ablation. In glass/film/film (GFF) PCAP touchscreens, the films are coated with indium-tin-oxide (ITO), patterned by printing silver ink, and by ablating both the ITO and silver with a laser. A similar process occurs for a glass/glass (2GS) PCAP touchscreen. Embodiments include varying the pattern with which the laser ablates ITO on film within the touch area to improve touchscreen sensitivity. For example, by varying the width of patterns of floating ITO islands such that widths are less than or equal to a plan-view electrode gap between vertical and horizontal electrode pads and larger elsewhere, the touch sensitivity of the PCAP touchscreen may be improved and/or maximum touchscreen size may be increased.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Application No. 62/834,817,filed on Apr. 16, 2019, entitled, PCAP Touchscreens with Varying ITODicing Patterns, which is incorporated herein by reference in itsentirety.

BACKGROUND Field

The present disclosure relates generally to Projected capacitive (PCAP)touch sensitive systems, and more specifically to the dicing patterns onindium-tin-oxide (ITO) of PCAP touchscreens.

Background Art

The ability to interact with computer applications via touch withdisplays is ubiquitous for today's consumers. While several touchtechnologies are possible to support touch interactions, each hasadvantages and disadvantages that tailor each for particularenvironments, sizes, and applications. Projected capacitive (PCAP)technology is commonly utilized to support characteristics expected fromtouch interactions in touch/display interface devices.

A typical approach to using lasers to ablate indium-tin-oxide (ITO) fora PCAP touchscreen includes uniform patterns on the ITO. But the uniformpatterns contribute to increasing a baseline mutual capacitance, C_(M),that reduces touch sensitivity of the PCAP touchscreen.

SUMMARY

System, method, combination, sub-combination and other embodiments areprovided for glass/film/film (GFF) and/or glass/glass (2GS) projectedcapacitive (PCAP) touchscreens and their construction. In a GFF PCAPtouchscreen, the films are coated with indium-tin-oxide (ITO) orequivalent, patterned by printing silver ink, and both the ITO andsilver are ablated with a laser. Any transparent conductive film, suchas silver-nanowire coating, that can be laser ablated is considered tobe an equivalent to ITO. In the descriptions that follow, it is to beunderstood that “ITO” is shorthand for “ITO or equivalent”. Similarly,in a 2GS PCAP touchscreen the ITO on the glass is patterned by printingsilver ink, and by ablating both the ITO and silver with the laser.Embodiments include varying the pattern with which the laser ablates ITOon film (or glass) within the touch area to improve touchscreensensitivity. For example, by varying the width of floating ITO islandssuch that widths are less than or equal to a plan-view electrode gapbetween vertical and horizontal electrode pads and larger elsewhere, thetouch sensitivity of the PCAP touchscreen may be improved and/or maximumtouchscreen size may be increased.

Some embodiments include a projected capacitive (PCAP) touchscreen thatincludes two transparent electrodes. The first transparent electrodeincludes a vertical electrode pad and a first floating ITO island. Thesecond transparent electrode is parallel to the first transparentelectrode, and includes a horizontal electrode. The vertical electrodepad is separated from the horizontal electrode by a plan-view electrodegap, and a dimension of the first floating ITO island is less than orequal to the plan-view electrode gap. Embodiments also include a methodfor fabricating a projected capacitive (PCAP) touchscreen by disposing afirst transparent electrode including a vertical electrode pad on afirst layer, and disposing a second transparent electrode including ahorizontal electrode on a second layer that is parallel to the firsttransparent electrode, where the vertical electrode pad is separatedfrom the horizontal electrode by a plan-view electrode gap. Embodimentsalso include creating via laser ablation, a first floating ITO island onthe first transparent electrode, where a dimension of the first floatingITO island is about equal to or less than the plan-view electrode gap.The dimension may be a width, for example.

In some embodiments, the second transparent electrode includes a secondfloating ITO island, and some embodiments include: establishing a firstlaser ablation line between the first floating ITO island and a firstneighboring floating ITO island of the first transparent electrode,where the first floating ITO island is most proximate to the verticalelectrode pad; and establishing a second laser ablation line between thesecond floating ITO island and a second neighboring floating ITO islandof the second transparent electrode, where the second floating ITOisland is most proximate to the horizontal electrode pad. In someembodiments, the first and the second laser ablation lines are centeredwithin the plan-view electrode gap. In some embodiments, the first laserablation line is not aligned with the second laser ablation line withinthe plan-view electrode gap. In some embodiments, the first floating ITOisland is smaller than one or more floating ITO islands of the firsttransparent electrode. Further, one or more floating ITO islands of thefirst transparent electrode may vary in length. In some embodiments, theone or more floating ITO islands of the first transparent electrode aresubstantially equivalent in length.

When the dimension of the first floating ITO island is based on avarying ITO dicing pattern, some embodiments include a first signal pathfrom the vertical electrode pad to the horizontal electrode pad via thefirst floating ITO island, where the first signal path includes at leastone high-impedance edge-to-edge capacitance or one high-impedancesmall-area capacitance, where the first signal path has a lowerimpedance than a second signal path from the vertical electrode pad tothe horizontal electrode pad via a second floating ITO island of thefirst transparent electrode, where the second floating ITO island isbased on a uniform ITO dicing pattern. In some embodiments, the varyingITO dicing pattern of the first floating ITO island causes a reductionin a value of mutual capacitance, C_(M), between the vertical electrodeand the horizontal electrode. In some embodiments, the varying ITOdicing pattern of the first floating ITO island causes a reduction inthe PCAP touchscreen RC settling time and an increase in touchsensitivity, ΔC_(M)/C_(M).

Further embodiments, features, and advantages of the present disclosure,as well as the structure and operation of the various embodiments of thepresent disclosure, are described in detail below with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The accompanying drawings, which are incorporated herein and form partof the specification, illustrate the present disclosure and, togetherwith the description, further serve to explain the principles of thedisclosure and to enable a person skilled in the relevant art(s) to makeand use the disclosure.

FIG. 1A illustrates a combination of a projected capacitive (PCAP)touchscreen with a display device, according to an exemplary embodimentof the disclosure;

FIG. 1B illustrates a cross-section of a glass/film/film PCAPtouchscreen, according to an exemplary embodiment of the disclosure;

FIG. 1C illustrates a cross-section of a glass/glass PCAP touchscreen,according to an exemplary embodiment of the disclosure;

FIG. 2A illustrates a plan view of a uniform indium-tin-oxide (ITO)dicing pattern, of a PCAP touchscreen;

FIG. 2B illustrates a plan view of vertical electrodes with a varyingITO dicing pattern of a PCAP touchscreen, according to an exemplaryembodiment of the disclosure;

FIG. 2C illustrates a plan view of horizontal electrodes with a varyingITO dicing pattern of a PCAP touchscreen, according to an exemplaryembodiment of the disclosure;

FIG. 2D illustrates a plan view of an overlay of vertical and horizontalelectrodes with a varying ITO dicing pattern of a PCAP touchscreen,according to an exemplary embodiment of the disclosure;

FIG. 2E illustrates a plan view of an overlay of vertical and horizontalelectrodes and a plan-view electrode gap of a PCAP touchscreen,according to an exemplary embodiment of the disclosure;

FIG. 3 illustrates a plan view of an overlay of vertical and horizontalelectrodes with another varying ITO dicing pattern of a PCAPtouchscreen, according to an exemplary embodiment of the disclosure;

FIG. 4A illustrates an exemplary example of a plan view of a verticalcross section of a uniform ITO dicing pattern;

FIG. 4B illustrates an exemplary example of a plan of a view verticalcross section of a varying ITO dicing pattern, according to an exemplaryembodiment of the disclosure;

FIG. 5A illustrates an exemplary example of a vertical cross section ofa uniform ITO dicing pattern;

FIG. 5B illustrates an exemplary example of vertical cross section of avarying ITO dicing pattern, according to an exemplary embodiment of thedisclosure;

FIGS. 5C, 5D, & 5E illustrate exemplary examples of vertical crosssections of other varying ITO dicing patterns, according to an exemplaryembodiments of the disclosure;

FIG. 6A illustrates an exemplary example of capacitive coupling with auniform ITO dicing pattern;

FIG. 6B illustrates an exemplary example of capacitive coupling of avarying ITO dicing pattern, according to an exemplary embodiment of thedisclosure;

FIGS. 6C, 6D, & 6E illustrate an exemplary examples of capacitivecoupling of other varying ITO dicing patterns, according to an exemplaryembodiments of the disclosure;

FIG. 7 illustrates an exemplary example of a plan-view overlap of avertical electrode neck and a horizontal electrode neck, according to anexemplary embodiment of the disclosure;

FIG. 8 illustrates an example computer system useful for implementingand/or using various embodiments.

FIGS. 9A & 9B illustrate an electronic principle that for seriesimpedances, high impedances dominate.

The present disclosure will now be described with reference to theaccompanying drawings. In the drawings, generally, like referencenumbers indicate identical or functionally similar elements.Additionally, generally, the left-most digit(s) of a reference numberidentifies the drawing in which the reference number first appears.

DETAILED DESCRIPTION

The following Detailed Description of the present disclosure refers tothe accompanying drawings that illustrate exemplary embodimentsconsistent with this disclosure. The exemplary embodiments will fullyreveal the general nature of the disclosure that others can, by applyingknowledge of those skilled in relevant art(s), readily modify and/oradapt for various applications such exemplary embodiments, without undueexperimentation, without departing from the spirit and scope of thedisclosure. Therefore, such adaptations and modifications are intendedto be within the meaning and plurality of equivalents of the exemplaryembodiments based upon the teaching and guidance presented herein. It isto be understood that the phraseology or terminology herein is for thepurpose of description and not of limitation, such that the terminologyor phraseology of the present specification is to be interpreted bythose skilled in relevant art(s) in light of the teachings herein.Therefore, the detailed description is not meant to limit the presentdisclosure.

The embodiment(s) described, and references in the specification to “oneembodiment”, “an embodiment”, “an example embodiment”, etc., indicatethat the embodiment(s) described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is understood that it iswithin the knowledge of one skilled in the art to effect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described.

FIG. 1A illustrates a combination 100 of a projected capacitive (PCAP)touchscreen 105 with a display device 110, according to an exemplaryembodiment of the disclosure. PCAP touchscreen 105 may be placed infront of display device 110 such as a monitor, computing device, acomputer, a laptop, a tablet, and/or a mobile computing device, to namejust some examples. PCAP touchscreen 105 also includes a connector (notshown) that electronically couples PCAP touchscreen 105 to displaydevice 110. A user can interact with software applications on displaydevice 110 by touching cover sheet touch surface 137 of touchscreen 105.Cross-section 120 of PCAP touchscreen 105 is described further in FIGS.1B and 1C.

FIG. 1B illustrates a cross-section 120A of a glass/film/film PCAPtouchscreen 105, according to an exemplary embodiment of the disclosure.For explanation purposes, FIG. 1B may be described with elements fromprevious figures. Cross-section 120A may include cover sheet 135,adhesive 143, transparent conductor 145, film 150, adhesive 153,transparent conductor 155, and film 160. A user interacts withtouchscreen 105 by touching cover sheet touch surface 137. Informationfrom the touch on cover sheet touch surface 137 is collected viatransparent conductors 145 and 155, and conveyed to display device 110electronically.

FIG. 1C illustrates a cross-section 120B of a glass/glass (2GS) PCAPtouchscreen 105, according to an exemplary embodiment of the disclosure.For explanation purposes, FIG. 1C may be described with elements fromprevious figures. Cross-section 120B may include cover sheet 175,transparent conductor 180, adhesive 183, transparent conductor 185, andback sheet 190. A user interacts with touchscreen 105 by touching coversheet touch surface 177. Information from the touch on cover sheet touchsurface 177 are collected via transparent conductors 180 and 185, andconveyed to display device 110 electronically. Other implementationsinclude but are not limited to a three glass (3GS) solution in which thecover sheet contains no electrodes and there are two back sheets eachwith electrodes.

Adhesive layers 143, 153, and 183 may be a solid optically clearadhesive (OCA) that can be an acrylic-based adhesive, a silicone-basedadhesive, polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or anyother suitable OCA that will be recognized by those skilled in therelevant art(s). Transparent conductors 145, 155, 180, and 185 arecircuitry layers that may include electrodes, routing traces, and traceshields of materials such as indium-tin-oxide (ITO), carbon nanotubes,graphene, silver-nanowires, silver, and/or metal mesh. (The transparentconductors 145, 155, 180, and 185 are typically microscopically thin,but for clarity they are not drawn to scale in FIGS. 1B and 1C.Furthermore, there is no air gap between adhesives and coversheets (e.g,adhesive 143 and cover sheet 135) or adhesives and a film (e.g.,adhesive 153 and film 160); adhesive 143 conforms to the inside surfaceof cover sheet 135 and transparent conductor 145 and adhesive 153 tofilm 150 and transparent conductor 155 which it turn conforms to film160 with no air gap.

FIG. 2A illustrates plan view 200 of a uniform ITO dicing pattern 215,of cross-section 120A through cover sheet touch surface 137 (orcross-section 120B through cover sheet touch surface 177.) Forexplanation purposes, FIG. 2A may be described with elements fromprevious figures. Plan view 200 includes for example, verticalelectrodes 210 a, 210 b, and 210 c formed of diamond shaped “pads”connected by narrow “necks” and outlined with gray highlighted dashedlines. The vertical electrodes stand out as dominantly white areas inplan view 200. In each vertical electrode 210, three necks, two fullpads and two half pads are shown. The thick shaded outlines of thevertical electrodes 210 a-210 c correspond to laser ablation paths ontransparent conductor 145 of film 150. Horizontal electrodes 205 a, 205b, and 205 c are shown as dashed lines that correspond to laser ablationpaths on transparent conductor 155. The necks of the horizontalelectrodes 205 a-205 c are shown overlapping in plan-view with the necksof the vertical electrodes.

The ITO of transparent conductor 145 of film 150 is “diced up” betweenvertical electrodes 210 a and 210 b and between vertical electrodes 210b and 210 c. The laser-ablation pattern for doing so is uniform ITOdicing pattern 215 represented by the fine solid lines in plan view 200.The ITO between horizontal electrodes 205 a and 205 b and betweenhorizontal electrodes 205 b and 205 c of transparent conductor 155 onfilm 160 also includes a laser-ablated uniform ITO dicing pattern.However, for clarity, this is not shown in plan view 200. The uniformITO dicing patterns (e.g., uniform ITO dicing pattern 215) createsfloating ITO islands that are floating transparent conductive islands ofuniform width. Furthermore, in plan-view, the dashed outlines ofhorizontal electrodes 205 a-c of transparent conductor 155 on film 160are well within the floating ITO islands most proximal to verticalelectrodes 210 a-c of transparent conductor 145 of film 150.

Uniform ITO dicing pattern 215 of plan view 200 includes sets of equallyspaced parallel lines. This results in many small diamond shapedfloating ITO islands of the same size. For simplicity, six uniformdicing patterns 215 are shown covering the center 6 diamond shaped padsof horizontal electrodes 205 a-c. Likewise the uniform ITO dicingpattern 215 (is not shown) is present to the left of vertical electrode210 a and to the right of vertical electrode 210 c. A cross section viewshown by line A will be discussed with regards to FIG. 4A below.

Creating dicing patterns, rather than full removal of the ITO betweenelectrodes, has two advantages. First, the dicing patterns reduce thetotal area of laser-ablated ITO, thus enabling the laser ablationprocess to be cost competitive. Second, the dicing patterns reduce thevisibility of the electrode pattern as a large fraction of the areabetween electrodes has the coating of ITO just like the electrodes. Inother words, the dicing patterns improve the optical uniformity of theoverlapping transparent conductors 145 and 155 when viewed through coversheet 135, for example. But, from an electronics perspective, the dicingpatterns have downsides. The presence of the floating ITO islandsincreases the baseline capacitance (C_(M)) between vertical andhorizontal electrodes resulting in increased touchscreen RC settlingtime, and reduced touchscreen sensitivity parameter, ΔC_(M)/C_(M). Someembodiments include a system and method for reducing these undesiredelectronic effects.

The baseline capacitance, C_(M), is the background capacitance thatoccurs on cross-section 120A or 120B before cross-section 120A or 120Bis touched. When cross-section 120A or 120B is touched, a change in thecapacitance, ΔC_(M), is detected. A smaller base baseline capacitance,C_(M), and a larger change in mutual capacitance, ΔC_(M), results in alarger value PCAP touchscreen sensitivity parameter, ΔC_(M)/C_(M).Having a larger value PCAP touchscreen sensitivity parameter,ΔC_(M)/C_(M), results in a more responsive PCAP touchscreen 105,Reducing C_(M) also allows for larger PCAP touchscreen sizes. Forexample, reducing the mutual capacitance, C_(M), associated with atouchscreen reduces the touchscreen RC settling time thus increasing theresponsiveness of a PCAP touchscreen.

Some embodiments include a system and method for reducing theseundesired electronic effects by varying the ITO patterns of PCAPtouchscreen 105. FIG. 2B overlaid onto FIG. 2C produces FIG. 2D. FIGS.2B, 2C, and 2D may be described with elements from previous figures.FIG. 2B illustrates plan view 220 of vertical electrodes 230 a-230 cwith a varying ITO dicing pattern 235 of PCAP touchscreen 105, accordingto an exemplary embodiment of the disclosure. Vertical electrodes 230a-230 c may be on transparent conductor 145 of cross-section 120A ofFIG. 1B, or on transparent conductor 180 of cross-section 120B of FIG.1C. Varying ITO dicing pattern 235 of plan view 220 results in floatingITO islands of different sizes compared to the uniform ITO dicingpattern 215 of FIG. 2A that results in floating ITO islands of uniformsize. Varying ITO dicing pattern 235 may include a pattern with dicingnumber of 5. For simplicity, six dicing patterns 235 are shown coveringthe center 6 diamond shaped pads of the horizontal electrodes, butdicing pattern 235 (not shown) is nevertheless present to the left ofvertical electrode 230 a and to the right of vertical electrode 230 c.

FIG. 2C illustrates plan view 240 of horizontal electrodes 260 a-260 cwith a varying ITO dicing pattern of a PCAP touchscreen, according to anexemplary embodiment of the disclosure. Horizontal electrodes 260 a-260c may be on transparent conductor 155 of cross-section 120A of FIG. 1B,or on transparent conductor 185 of cross-section 120B of FIG. 1C. Whilevarying ITO dicing pattern 265 of plan view 240 is shown as a shadingpattern for convenience, varying ITO dicing pattern 265 results indiamond shaped floating ITO islands of different sizes compared touniform ITO dicing pattern 215 or the uniform ITO dicing pattern (notshown) in FIG. 2A that result in uniform-sized floating ITO islands. Forsimplicity, six dicing patterns 265 are shown as shaded in the center 6diamonds, but dicing pattern 265 (not shown) are present in each diamondadjacent to horizontal electrode 260 a and 260 c as well. Varying ITOdicing pattern 265 may be similar or different than varying ITO dicingpattern 235 of FIG. 2B.

FIG. 2D illustrates plan view 270 of an overlay of vertical electrodes230 a-230 c and horizontal electrodes 260 a-260 c with respectivevarying ITO dicing patterns 235 and 265 of PCAP touchscreen 105,according to an exemplary embodiment of the disclosure. Varying ITOdicing pattern 235 on transparent conductor 145 of cross-section 120A ofFIG. 1B, or on transparent conductor 180 of cross-section 170 of FIG. 1Care shown. For simplicity, varying ITO dicing pattern 265 of transparentconductor 155 of cross-section 120A of FIG. 1B, or on transparentconductor 185 of cross-section 170 of FIG. 1C are not shown. Varying ITOdicing pattern 265 would be located behind the vertical electrode padsof vertical electrodes 230 a-230 c.

FIG. 2E illustrates plan view 280 of an overlay of vertical electrodes230 a and 230 b and horizontal electrodes 260 a and 260 b, and plan-viewelectrode gaps 290 a-290 d of PCAP touchscreen 105, according to anexemplary embodiment of the disclosure. FIG. 2E may be described withelements from previous figures. For clarity, varying ITO dicing patterns235 and 265 are not shown. Plan-view electrode gap 290 is formed betweentwo regions of transparent conductor formed by laser ablation, and is adistance between a vertical electrode and a horizontal electrode in aplan view. For example, plan-view electrode gap 290 b is the distancebetween horizontal electrode ablation line 269 shown as a dashed lineand vertical electrode ablation line 232 shown as a dashed line with agray highlight.

FIG. 3 illustrates a plan view 300 of an overlay of vertical electrodes230 a and 230 b and horizontal electrodes 260 a and 260 b with adifferent varying ITO dicing pattern 310 of a PCAP touchscreen,according to an exemplary embodiment of the disclosure. FIG. 3 may bedescribed with elements from previous figures. In this example, varyingITO dicing pattern 310 may be a dicing pattern with a dicing number of7. As shown, the dicing pattern is the same as in FIG. 2A except for theaddition of laser ablation lines close to and following the outlines ofthe vertical electrodes. For example, laser ablation line 320 isproximate to and follows the left edge of vertical electrode 230 c whilelaser ablation line 330 is proximate to and follows the right edge ofvertical electrode 230 b. A varying ITO dicing pattern (not shown) thatcorresponds with the transparent conductor of horizontal electrodes 260a-260 b may be the same as varying ITO dicing pattern 310, 235, 265, ora different varying ITO dicing pattern.)

FIG. 4A illustrates an exemplary example of plan view 400 of a verticalcross section of uniform ITO dicing pattern 215 of FIG. 2A. FIG. 4A maybe described with elements from previous figures. Plan-view electrodegaps 405 a-405 d are distances between the vertical electrodes 210 b and210 c shown as dashed lines with a gray highlight and the horizontalelectrode 205 c shown as dashed lines as shown in FIG. 2A. For example,plan-view electrode gap 405 a is a distance between vertical electrode210 b and horizontal electrode 205 c; plan-view electrode gap 450 b is adistance between vertical electrode 210 c and horizontal electrode 205c; plan-view electrode gap 450 c is a distance between verticalelectrode 210 c and horizontal electrode 205 c; and plan-view electrodegap 450 d is a distance between vertical electrode 210 b and horizontalelectrode 205 c. The cross section of plan view 400 across line A isillustrated further in FIGS. 5A and 6A below.

FIG. 4B illustrates an exemplary example of plan view 410 of a verticalcross section of a varying ITO dicing pattern 235 of FIG. 2B, accordingto an exemplary embodiment of the disclosure. FIG. 4B may be describedwith elements from previous figures. The cross section of plan view 410across line B is further illustrated in FIGS. 5B and 6B below. Plan-viewelectrode gaps 450 a-450 d are shown based on vertical electrode 230 band 230 c and horizontal electrode 260 c of FIG. 2D. Plan-view electrodegaps 450 a-450 d of FIG. 4B may be the same width as plan-view electrodegaps 405 a-405 d of FIG. 4A.

For example, plan-view electrode gap 450 a is a distance betweenvertical electrode ablation line 420 and horizontal electrode ablationline 440; plan-view electrode gap 450 b is a distance between verticalelectrode ablation line 425 and horizontal electrode ablation line 440;plan-view electrode gap 450 c is a distance between vertical electrodeablation line 425 and horizontal electrode ablation line 445; andplan-view electrode gap 450 d is a distance between vertical electrodeablation line 420 and horizontal electrode ablation line 445.

Vertical electrode ablation line 420 is between vertical electrode 230 band most proximate floating island 423. Laser ablation line 430 isbetween most proximate floating island 423 and neighboring floatingisland 455. In addition, vertical electrode ablation line 425 is betweenvertical electrode 230 c and most proximate floating island 428. Laserablation line 435 is between most proximate floating island 428 andneighboring floating island 465.

Horizontal electrode ablation line 440 is between horizontal electrode260 c and most proximate floating island 433. Laser ablation line 430′is between most proximate floating island 433 and neighboring floatingisland 555 (see FIGS. 5B and 5C.) Further, horizontal electrode ablationline 445 is between horizontal electrode 260 c and most proximatefloating island 448. Laser ablation line 435′ is between most proximatefloating island 448 and neighboring floating island 565 (see FIGS. 5Band 5C).

In some embodiments laser ablation lines 430 and 435 are laser ablatedon transparent conductor 145 of FIG. 1B (along with vertical electrodes210 a-210 c) or transparent conductor 180 of FIG. 1C (along withvertical electrodes 210 a-210 c.) In some embodiments, laser ablationlines 430 and 435 are centered within respective plan-view electrodegaps (e.g., plan-view electrode gap 450 a for laser ablation line 430and plan-view electrode gap 450 c for laser ablation line 435.) In someembodiments, one of laser ablation lines 430 and 435 is centered withintheir respective plan-view electrode gap and the remaining laserablation line is not centered within their respective plan-viewelectrode gap.

Other laser ablation lines 430′ and 435′ (not shown in FIG. 4B; see FIG.5B below) may be laser ablated on transparent conductor 155 of FIG. 1B(along with horizontal electrodes 260 a-260 c) or transparent conductor185 of FIG. 1C (along with horizontal electrodes 260 a-260 c.) In someembodiments, laser ablation line 430′ and 435′ are centered within arespective plan-view electrode gap (e.g., plan-view electrode gap 450 afor laser ablation line 430′ and plan-view electrode gap 450 c for laserablation line 435′.) In some embodiments, one of laser ablation lines430′ and 435′ is centered within their respective plan-view electrodegap 450 and the remaining laser ablation line is not centered withintheir respective plan-view electrode gap 450.

FIG. 5A illustrates an exemplary example of a vertical cross section 500across line A of uniform ITO dicing pattern 215 of FIG. 2A. FIG. 5A maybe described with elements from previous figures. ITO electrodes aresolid black while floating islands resulting from the dicing pattern arerepresented as narrow open rectangles. Vertical cross section 500includes electrodes 210 b and 210 c, as well as horizontal electrode 205c of FIG. 2A. Note that uniform ITO dicing pattern 215 of FIG. 2Aresults in uniformly sized and spaced floating ITO islands and that theuniformly sized and spaced floating ITO islands on the transparentconductor of the vertical or the horizontal electrodes are equal to orlarger than plan-view electrode gaps 405 a/450 a or 405 c/450 c, whereplan-view electrode gaps 450 a and/or 450 c may be equal to plan-viewelectrode gap 405 a and/or 405 c of FIG. 4A.

FIG. 5B illustrates an exemplary example of vertical cross section 550across line B of varying ITO dicing pattern 235, according to anexemplary embodiment of the disclosure. FIG. 5B may be described withelements from previous figures. As described above, ITO electrodes aresolid black while floating islands resulting from the dicing pattern arerepresented as narrow open rectangles. FIG. 5B includes verticalelectrodes 230 b and 230 c of FIG. 2B (and FIG. 2D), and horizontalelectrode 260 c of FIG. 2C (and FIG. 2D). In some embodiments, varyingITO dicing pattern 235 of FIG. 2B (and FIG. 2D) results in differentsized floating ITO islands on the same transparent conductor 145 or 180as that of the vertical electrodes 230 b and 230 c. In some embodiments,varying ITO dicing pattern 265 of FIG. 2C (and FIG. 2D) results indifferent sized floating ITO islands on the transparent conductor 155 or185 as that of the horizontal electrode 260 c. In some embodiments, thedimension is width, and widths of the floating ITO islands are smallernear the boundaries between the vertical electrode pads of verticalelectrodes 230 b and 230 c and the horizontal electrode pad ofhorizontal electrode 260 c and larger elsewhere.

In some embodiments, a dimension of one floating ITO island of thetransparent conductor of vertical electrodes 230 b and 230 c and/or ofhorizontal electrode 260 c, is less than plan-view electrode gaps 450 aor 450 c, where plan-view electrode gaps 450 a and/or 450 c may be equalto plan-view electrode gap 405 a and/or 405 c of FIG. 4A and/orplan-view electrode gap 290 a and/or 290 c of FIG. 2E. In someembodiments, a dimension such as width, of one floating ITO island(e.g., most proximate floating ITO island 423 or 428) of the transparentconductor of the vertical electrodes 230 b and 230 c and/or a dimensionof one floating ITO island (e.g., most proximate floating ITO island 433or 448) of the horizontal electrode 260 c, is less than or approximatelyequal to the plan-view electrode gap 450 a or 450 c. Again, plan-viewelectrode gaps 450 a and/or 450 c may be equal to plan-view electrodegap 405 a and/or 405 c of FIG. 4A, or equal to plan-view electrode gap290 a and/or 290 c of FIG. 2E.

In some embodiments laser ablation lines 430 and 430′ are aligned. Insome embodiments laser ablation lines 430 and 430′ are both centeredwithin a plan-view electrode gap (e.g., plan-view electrode gap 450 a)and they are also aligned with each other. In some embodiments laserablation lines 435 and 435′ are aligned. In some embodiments laserablation lines 435 and 435′ are both centered within a plan-viewelectrode gap (e.g., plan-view electrode gap 450 c) and they are alsoaligned with each other. In some embodiments laser ablation lines 430and 430′ are both centered within a plan-view electrode gap (e.g.,plan-view electrode gap 450 a) and laser ablation lines 430 and 430′ arealso aligned with each other, and laser ablation lines 435 and 435′ areboth centered within a plan-view electrode gap (e.g., plan-viewelectrode gap 450 c) and laser ablation lines 435 and 435′ are alsoaligned with each other.

FIG. 5C illustrates an exemplary example of vertical cross section 570of another varying ITO dicing pattern, according to an exemplaryembodiment of the disclosure. Vertical cross section 570 is similar tovertical cross section 550 with regards to one or more floating ITOislands (e.g., most proximate floating ITO islands 423, 428, 433, and/or448) being less than a plan-view electrode gap 450. But, the remainingfloating islands in one or more transparent conductors associated withthe vertical electrodes 230 b and 230 c and/or horizontal electrode 260c are equal in size.

FIG. 5D illustrates an exemplary example of vertical cross section 580of another varying ITO dicing pattern, according to an exemplaryembodiment of the disclosure. Vertical cross section 580 is similar tovertical cross section 550 except that proximate floating ITO islands573, 578, 583 and 588 fill the plan-view electrode gap 450 rather thanbeing more narrow than the plan-view electrode gap 450. In plan-view,vertical electrode ablation line 420 lines up with ablation line 420′between proximate floating island 583 a neighboring floating island 581.Likewise horizontal ablation line 440 lines up with ablation line 440′between proximate floating island 573 and neighboring floating island575, and horizontal ablation line 445 lines up with ablation line 445′between proximate floating island 578 and neighboring floating island577, and, vertical ablation line 425 lines up with ablation line 425′between proximate floating island 588 and a neighboring floating island589. [0061.] FIG. 5E illustrates an exemplary example of vertical crosssection 590 of another varying ITO dicing pattern, according to anexemplary embodiment of the disclosure. Vertical cross section 590 issimilar to vertical cross section 580 except that proximate floatingislands 573, 578, 583 and 588 of cross section 580 are each split inhalf by additional laser ablation lines 595, 595′, 596 and 596′. Forvertical cross section 590, laser ablation line 595 is between proximatefloating island 591A and neighboring floating island 592A. Likewiselaser ablation line 595′ is between proximate floating island 594A andneighboring floating island 593A, and laser ablation line 596 is betweenproximate floating island 592B and neighboring floating island 591B,and, laser ablation line 596′ is between proximate floating island 593Band neighboring floating island 594B. In plan-view, laser ablation line595 lines up with laser ablation line 595′ and laser ablation line 596lines up with laser ablation line 596′. It remains true that, inplan-view, laser ablation line 420 lines up with laser ablation line420′, laser ablation line 425 lines up with laser ablation line 425′,laser ablation line 440 lines up with laser ablation line 440′, andlaser ablation line 445 lines up with laser ablation line 445′.

FIGS. 6A-6E illustrate capacitive couplings for the electrode geometriesof FIGS. 5A-5E. To better appreciate FIGS. 6A-6E, keep in mind theelectronic principle that for a signal path containing two or moreimpedances in series, the value of the total impedance of the signalpath is dominated by larger of the series impedances. This principle isuseful for the identification of the lowest impedance signal pathsbetween electrodes. The lowest impedance path(s) contribute most to themutual capacitance C_(M) between electrodes.

A signal path may include a set of impedances in series that connect avertical electrode to a horizontal electrode. There are many such signalpaths that connect the vertical electrode to the horizontal electrode.Of the many signal paths between electrodes the signal path with thelowest impedance is most important in the sense of contributing most toC_(M). This reflects the fact that electricity, like water, tends tofollow the path of least resistance. This leaves the problem ofidentifying the path of least resistance, i.e. the signal path or pathswith the lowest impedances.

To identify the signal path(s) of lowest impedance we need to considerthe total impedance of each signal path one at a time. For this step theprinciple illustrated by FIGS. 9A and 9B, shows that the value of totalor net impedance of a set of impedances in series is dominated by thelargest impedance(s) in the path. An analogy here is that the maximumamount of traffic a road system can handle is determined by the trafficbottlenecks (e.g., high impedances to traffic), not sections of roadwith many lanes moving freely (e.g., low impedance to traffic). Thus,high impedance elements determine which signal paths have the lowestimpedance.

FIGS. 9A & 9B illustrate the electronic principle that for a series ofimpedances containing higher and lower impedances, the higher impedancesdominate the resulting net or total impedance. To start with the morefamiliar, it helps to first consider example 900 of FIG. 9A regardingresistors as a warm-up to considering series capacitors. Series resistorchain 910 includes a 10Ω resistor “R1” in series with a 1Ω resistor“R2”. The total series resistance “R_(SERIES)” equals 11Ω, which is only10% different from the R1 resistance of 100 but an order of magnitudedifferent from the R2 resistance of 1Ω. The higher resistance R1dominates the series resistance R_(SERIES). The resistor chain 920 withonly R1 has approximately the same resistance as the series resistorchain 910 with both R1 and R2. The effect of R2 is negligible. Similarprinciples apply to example 950 of FIG. 9B with series capacitor chains930 and 940, except that the reactive impedance of capacitors plays therole of resistance. In this example, capacitor C1 has a smallercapacitance of 1 pF and capacitor C2 has larger capacitance of 10 pF.Smaller capacitance means bigger impedance, as made clear by theelectronics formula for |Z|=1/(2πfC) where C is capacitance, f isfrequency, and |Z| is the magnitude of impedance. For example, at afrequency of 10 kHz, C1 has a relatively large impedance of 16 MΩ and C2has a relatively small impedance of 1.6 MΩ. The series capacitance of C1and C2 is equal to C_(SERIES)=0.9 pF, for an impedance of 18 MΩ, whichis only 10% different from the 1 pF capacitance (16 MΩ impedance) of thehigh impedance C1 and an order of magnitude different from the 10 pFcapacitance of the low impedance C2. In series chains of capacitors, thedominant effects come from higher impedance capacitors, that is theseries capacitors with the smaller values of capacitance.

As described earlier, capacitive coupling exists between adjacent ITOregions, including between floating ITO islands and electrode pads(vertical and horizontal.) For example, an ITO region in an upper film(e.g., transparent conductor 145 of film 150) and an ITO region in thelower film (e.g., transparent conductor 155 of film 160) that overlap inplan-view create a parallel plate capacitor. The capacitance of aparallel plate capacitor is given approximately (neglecting fringefields) by the formula C=εA/d where A is the area of overlap of avertical electrode pad and a horizontal electrode pad, d is the distancebetween the vertical electrode pad and the horizontal electrode pad, ands is the dielectric constant of the material between the ITO layers.Such “parallel-plate” capacitances are represented in FIGS. 6A-6E belowby capacitor symbols with horizontal plates. There is also a capacitivecoupling between neighboring ITO regions within the same transparentconductor. Such “edge-to-edge” capacitances are represented by capacitorsymbols with vertical plates. Electrodes in actual capacitor circuitcomponents are parallel rather than edge-to-edge. Edge-to-edgecapacitances (in units of pF) tend to be much smaller than theparallel-plate capacitances and thus edge-to-edge capacitances tend tohave much higher impedances than parallel-plate capacitances.Accordingly, the edge-to-edge capacitances represent greater barriers totransient signal propagation compared to the parallel-platecapacitances. An exception is the case in which the area “A” of aparallel plate capacitor is very small, for example if the width of area“A” is comparable to or smaller than the distance “d” between theparallel plate electrodes. In FIGS. 6B-6C and FIG. 6E the possibility ofsuch exceptional parallel plate capacitors are indicated by verticaldotted lines rather than solid lines leaving the parallel plates symbolof the capacitance. Such parallel plate capacitors of exceptionallysmall capacitance, may be regarded as high impedance capacitances justlike the edge-to-edge capacitances.

The formula Q=CV applies to PCAP touchscreen 105 where C is thecapacitance coupling between electrodes, V is the drive voltage applied,and Q represents the charge detected at the sensing (e.g., receiving)electronics. In this context, this formula may be rewritten asQ_(SENSE)=C_(M)V_(DRIVE) where Q_(SENSE) is the integrated chargedetected by the receiving electronics, C_(M) is the mutual capacitancebetween drive and sense electrodes, and V_(DRIVE) is the excitationvoltage on the drive electrode. In electrode designs including floatingislands, such as in FIGS. 5A-5E, the measured mutual capacitance C_(M)is the net effect of a complex network of capacitances between thevarious regions of ITO. FIGS. 6A-6E illustrate such complex networks ofcapacitances. To understand the connection between such complex networksof capacitances and the resulting measurement mutual capacitance C_(M),it helps to keep in mind that the smaller edge-to-edge and very narrowparallel-plate capacitances dominate the impedance of series capacitancechains. As discussed below, more high-impedance edge-to-edge andsmall-area capacitances in series means more impedance which means lessmutual capacitance C_(M) between the vertical and horizontal electrodes.Reduced C_(M) correlates to a smaller RC time constant allowing thetouchscreen to keep up with a faster drive frequency (e.g., drivevoltage) and hence faster and/or more accurate data collection. ReducedC_(M) also means greater ΔC_(M)/C_(M) for better touch sensitivity.

In FIGS. 6A-6E, the dotted arrow lines represent transient signal pathswith lower “impedance.” The lower-impedance transient signal pathsinvolve fewer high-impedance edge-to-edge or small-area parallel-placecapacitances. The lowest-impedance transient signal path involves theleast number of high-impedance edge-to-edge or small-area capacitances.In example 600 of FIG. 6A there is one signal path that avoidshigh-impedance capacitances. This signal path 608 from verticalelectrode 210 b to horizontal electrode 205 c goes through parallelplate capacitances 621 a, 610 a and 620 a. This low-impedance signalpath dominates the mutual capacitance C_(M) between vertical electrode201 b and horizontal electrode 205 c. Here, dominates means that signalpath 608 is transmits more signal than the other possible paths. Theresult is a larger value of C_(M) that undesirably increases thetouchscreens RC settling time as well as undesirably reduces the touchsensitivity ΔC_(M)/C_(M). Alternate signal paths such as signal paths607 and 609 contribute much less to the value of C_(M). Signal path 607includes high-impedance edge-to-edge capacitance 630 a (andlow-impedance parallel plate capacitance 620 a) and signal path 609includes high-impedance edge-to-edge capacitance 640 a (andlow-impedance parallel plate capacitance 621 a). Hence they both includeone edge-edge capacitance instead of none, so signal path 608 dominates.Signal path 608 also dominates any signal path through capacitance 622 a(623 a) as such paths between electrodes include high-impedanceedge-to-edge capacitance 632 a (642 a). Relative to the electrode designof FIG. 6A, the electrode designs of FIGS. 6B-6E reduce the value ofC_(M) leading to desirable reductions in the touchscreens RC settlingtime as well as desirable increases in the touch sensitivityΔC_(M)/C_(M).

For the improved designs in FIGS. 6B-6E, the lowest-impedance signalpaths include at least one high-impedance edge-to-edge or small-areacapacitance. In FIGS. 6B-6D, the lowest-impedance signal paths includetwo high-impedance capacitances. FIG. 6B illustrates an exemplaryexample 650 of capacitive coupling with varying ITO dicing pattern 235and/or varying ITO dicing pattern 265, according to an exemplaryembodiment of the disclosure. In example 650 of FIG. 6B there are foursignal paths including two high-impedance capacitances. Signal path 617includes edge-to-edge capacitances 630 b and 632 b (and low-impedancecapacitance 620 b). Similarly signal path 691 includes edge-to-edgecapacitances 640 b and 642 b (and low-impedance capacitance 621 b).Signal path 618 includes high-impedance small-area capacitance 610 b andhigh-impedance edge-to-edge capacitance 632 b (and low-impedancecapacitances 620 b and 621 b); not shown is a similar path throughhigh-impedance small-area capacitance 612 b and high-impedanceedge-to-edge capacitance 642 b (and low-impedance capacitors 620 b and621 b). Signal paths through capacitance 622 b (623 b) include a thirdhigh-impedance capacitance 634 b (644 b) and hence contribute less toC_(M). As the design of FIG. 6B has at least two high-impedances insignal paths between the electrodes, compared to no high-impedances inthe lowest impedance path 608 of FIG. 6A, the design of FIG. 6B providesan improved design with a desired lower value mutual capacitance CMbetween electrodes 201 b and 205 c. The same conclusion applies toexample 670 of FIG. 6C as can be seen by repeating the above argumentswith signal paths 637, 368 and 369 replacing signal paths 617, 618 and619 respectively as well as replacing capacitances 610 b, 612 b, 620 b,621 b, 622 b, 623 b, 630 b, 632 b, 634 b, 640 b, 642 b, 644 b withcapacitances 610 c, 612 c, 620 c, 621 c, 622 c, 623 c, 630 c, 632 c, 634c, 640 c, 642 c, 644 c respectively in example 650 of FIG. 6B.

FIG. 6D illustrates an exemplary example 680 of capacitive coupling withvarying ITO dicing pattern 235 and/or varying ITO dicing pattern 265,according to an exemplary embodiment of the disclosure. In example 680,there are no signal paths between the vertical electrode pads (e.g.,vertical electrode pad of vertical electrode 230 b) and horizontalelectrode pads (e.g., horizontal electrode pad of horizontal electrode260 c) involving zero or only one high-impedance edge-to-edge (or smallarea) capacitance. The dominant source of capacitive coupling betweenhorizontal and vertical pads is expected to come from thelowest-impedance transient signal paths 647, 648 and 649 that involvetwo high-impedance edge-to-edge capacitances in series (e.g., 630 d and632 d; or 632 d and 642 d; or 640 d and 642 d.) Hence, varying ITOdicing pattern (e.g., 235 or 265) reduces baseline C_(M) contributionsfrom pad-to-pad capacitive coupling (e.g., a pad of vertical electrode230 b to a pad of horizontal electrode 260 c capacitive coupling.) Othercapacitive-coupling signal paths involve three or more high-impedanceedge-to-edge capacitances. For example, other capacitive-coupling signalpaths include: i) edge-to-edge capacitances 630 d, 632 d, 634 d, andparallel-plate capacitance 622 d; and ii) edge-to-edge capacitances 640d, 642 d, 644 d and parallel-plate capacitance 623 d. Signal paths 647,649 and 648 also include capacitances 620 d, 621 d, or 611 d, 620 d, and621 d respectively, but these are larger parallel-plate capacitancesthat are dominated by the higher-impedance capacitances. Thus, thetransient signal paths 647, 648 and 649 indicated by the dotted linesare the lowest-impedance signal paths and they dominate (e.g., transmitmore signal) capacitive coupling between the electrode pads 230 b and260 c.

FIG. 6E illustrates an exemplary example 690 of capacitive coupling withvarying ITO dicing pattern 235 and/or varying ITO dicing pattern 265,according to an exemplary embodiment of the disclosure. In example 690,there are no signal paths between the vertical electrode pads (e.g.,vertical electrode pad of vertical electrode 230 b) and horizontalelectrode pads (e.g., horizontal electrode pad of horizontal electrode260 c) involving zero, only one, or even only two high-impedanceedge-to-edge (or small area) capacitances. The dominant source ofcapacitive coupling between horizontal and vertical pads is expected tocome from the two lowest-impedance transient signal paths 657 and 659that involve three high-impedance edge-to-edge capacitances in series,namely 630 e, 632 e and 633 e, or 640 e, 642 e and 643 e respectively.Signal paths 657 and 659 also include capacitances 620 e and 621 erespectively, but these are larger parallel-plate capacitances that aredominated by the higher-impedance capacitances. Signal path 658 isrelatively less important because it includes one high-impedancesmall-area capacitance 610 e in addition to three high-impedanceedge-to-edge capacitances 643 e, 632 e and 633 e. Likewise, any signalpath through high-impedance small-area capacitance 612 e will include atleast four high-impedance capacitances. Other capacitive-coupling signalpaths involve four or more high-impedance edge-to-edge capacitances. Forexample, other capacitive-coupling signal paths include: i) edge-to-edgecapacitances 630 e, 632 e, 633 e, 634 e, and parallel-plate capacitance622 e; and ii) edge-to-edge capacitances 640 e, 642 e, 643 e, 644 e andparallel-plate capacitance 623 e. Hence, example 690 of FIG. 6E isanother example of a varying ITO dicing pattern (e.g., 235 or 265) thatreduces baseline C_(M) contributions from pad-to-pad capacitive coupling(e.g., vertical electrode pad 230 b to horizontal electrode pad 260 ccapacitive coupling.)

In addition, a varying ITO dicing pattern (e.g., 235, 265) not onlydecreases C_(M), but may also increase ΔC_(M). In some cases, thevarying ITO dicing pattern may increase the number of electric fieldlines reaching the cover sheet touch surface 137 or cover sheet touchsurface 177 compared to uniform ITO dicing pattern 215. If so, a touchon cover sheet touch surface 137 or cover sheet touch surface 177results in a larger ΔC_(M).

By reducing C_(M) and perhaps increasing ΔC_(M), the PCAP touchscreensensitivity ratio, ΔC_(M)/C_(M), is increased. Furthermore, reducingC_(M) reduces the RC time constant associated with the PCAP touchscreen.These improvements in touchscreen electronic parameters promise improvedtouch sensitivity and/or increased maximum touchscreen size.

Referring to FIGS. 5B-5E and 6B-6E, it may be noted that wheneverablation lines line up in plan-view, the signal path is forced to gothrough a high-impedance edge-to-edge capacitance. This makes plan-viewaligned ablation lines, like 430 and 430′, 435 and 435′, 440 and 440′,445 and 445′, 595 and 959′, and 596 and 596′ a desirable feature ofthese designs.

FIG. 7 illustrates an exemplary example of a plan-view overlap 700 of avertical electrode neck and a horizontal electrode neck, according to anexemplary embodiment of the disclosure. The overlap of the necks(lightly shaded) creates a parallel-plate capacitance C_(NECK-TO-NECK)that may be referred to as the “neck-to-neck capacitance.” In contrast,“pad-to-pad capacitance” and the symbol C_(PAD-TO-PAD) 710 describe thecapacitances in the above embodiments. The lightly dotted ellipses inthe drawing below indicate the regions associated with the pad-to-padcapacitance, C_(PAD-TO-PAD) 710. If the pad-to-pad capacitance,C_(PAD-TO-PAD) 710, is large compared to the neck-to-neck capacitance,C_(NECK-TO-NECK) 720, then the benefits of varying ITO dicing patternwill have a significant percentage effect on baseline C_(M) values. Incontrast, if the neck-to-neck capacitance, C_(NECK-TO-NECK) 720, islarge compared to the pad-to-pad capacitance C_(PAD-TO-PAD) 710, thenthe varying dicing pattern may have less effect on baseline C_(M)values. However, even if C_(NECK-TO-NECK) 720>>C_(PAD-TO-PAD) 710, thevarying ITO dicing pattern may still have a significant effect on touchsensitivity ΔC_(M)/C_(M) due to an increase in ΔC_(M).

Various embodiments can be implemented, for example, using one or morewell-known computer systems, such as computer system 800 shown in FIG.8. Computer system 800 can be any well-known computer capable ofperforming the functions described herein such as PCAP touchscreen 105of FIG. 1 and/or display device 110. Computer system 800 may be internalor external to PCAP touchscreen 105 and/or display device 110 asdiscussed above. For example, portions of computer system 800 may beincluded as PCAP touchscreen 105 and/or display device 110. In addition,PCAP touchscreen 105 may be used in conjunction with another computersystem 800.

Computer system 800 includes one or more processors (also called centralprocessing units, or CPUs), such as a processor 804. Processor 804 isconnected to a communication infrastructure or bus 906. One or moreprocessors 804 may each be a graphics processing unit (GPU). In anembodiment, a GPU is a processor that is a specialized electroniccircuit designed to process mathematically intensive applications. TheGPU may have a parallel structure that is efficient for parallelprocessing of large blocks of data, such as mathematically intensivedata common to computer graphics applications, images, videos, etc.Computer system 900 also includes user input/output device(s) such asmonitors, keyboards, pointing devices, etc., that communicate withcommunication infrastructure 806 through user input/output interface(s)802.

Computer system 800 also includes a main or primary memory 808, such asrandom access memory (RAM). Main memory 908 may include one or morelevels of cache. Main memory 808 has stored therein control logic (i.e.,computer software) and/or data. Computer system 800 may also include oneor more secondary storage devices or memory 810. Secondary memory 810may include, for example, a hard disk drive 812 and/or a removablestorage device or drive 814. Removable storage drive 814 may be a floppydisk drive, a magnetic tape drive, a compact disk drive, an opticalstorage device, tape backup device, and/or any other storagedevice/drive.

Removable storage drive 814 may interact with a removable storage unit818. Removable storage unit 818 includes a computer usable or readablestorage device having stored thereon computer software (control logic)and/or data. Removable storage unit 818 may be a floppy disk, magnetictape, compact disk, DVD, optical storage disk, and/any other computerdata storage device. Removable storage drive 814 reads from and/orwrites to removable storage unit 818 in a well-known manner.

According to an exemplary embodiment, secondary memory 810 may includeother means, instrumentalities or other approaches for allowing computerprograms and/or other instructions and/or data to be accessed bycomputer system 800. Such means, instrumentalities or other approachesmay include, for example, a removable storage unit 822 and an interface820. Examples of the removable storage unit 822 and the interface 820may include a program cartridge and cartridge interface (such as thatfound in video game devices), a removable memory chip (such as an EPROMor PROM) and associated socket, a memory stick and USB port, a memorycard and associated memory card slot, and/or any other removable storageunit and associated interface.

Computer system 800 may further include a communication or networkinterface 824. Communication interface 824 enables computer system 800to communicate and interact with any combination of remote devices,remote networks, remote entities, etc. (individually and collectivelyreferenced by reference number 828). For example, communicationinterface 824 may allow computer system 800 to communicate with remotedevices 828 over communications path 826, which may be wired, and/orwireless, and which may include any combination of LANs, WANs, theInternet, etc. Control logic and/or data may be transmitted to and fromcomputer system 800 via communication path 826.

In an embodiment, a tangible, non-transitory apparatus or article ofmanufacture comprising a tangible computer useable or readable mediumhaving control logic (software) stored thereon is also referred toherein as a computer program product or program storage device. Thisincludes, but is not limited to, computer system 800, main memory 808,secondary memory 810, and removable storage units 818 and 822, as wellas tangible articles of manufacture embodying any combination of theforegoing. Such control logic, when executed by one or more dataprocessing devices (such as computer system 800), causes such dataprocessing devices to operate as described herein.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the disclosure.However, it will be apparent to one skilled in the art that specificdetails are not required in order to practice the disclosure. Thus, theforegoing descriptions of specific embodiments of the disclosure arepresented for purposes of illustration and description. They are notintended to be exhaustive or to limit the disclosure to the preciseforms disclosed; obviously, many modifications and variations arepossible in view of the above teachings. The embodiments were chosen anddescribed in order to best explain the principles of the disclosure andits practical applications, they thereby enable others skilled in theart to best utilize the disclosure and various embodiments with variousmodifications as are suited to the particular use contemplated. It isintended that the following claims and their equivalents define thescope of the disclosure.

Based on the teachings contained in this disclosure, it will be apparentto persons skilled in the relevant art(s) how to make and useembodiments of the disclosure using data processing devices, computersystems and/or computer architectures other than that shown in FIG. 8.In particular, embodiments may operate with software, hardware, and/oroperating system implementations other than those described herein.

It is to be appreciated that the Detailed Description section, and notthe Abstract section, is intended to be used to interpret the claims.The Abstract section may set forth one or more, but not all exemplaryembodiments, of the disclosure, and thus, are not intended to limit thedisclosure and the appended claims in any way.

The disclosure has been described above with the aid of functionalbuilding blocks illustrating the implementation of specified functionsand relationships thereof. The boundaries of these functional buildingblocks have been arbitrarily defined herein for the convenience of thedescription. Alternate boundaries may be defined so long as thespecified functions and relationships thereof are appropriatelyperformed.

It will be apparent to those skilled in the relevant art(s) that variouschanges in form and detail can be made therein without departing fromthe spirit and scope of the disclosure. Thus the disclosure should notbe limited by any of the above-described exemplary embodiments. Further,the claims should be defined only in accordance with their recitationsand their equivalents.

What is claimed is:
 1. A projected capacitive (PCAP) touchscreen,comprising: a first transparent electrode comprising a verticalelectrode pad and a first floating indium-tin-oxide (ITO) island; and asecond transparent electrode parallel to the first transparentelectrode, comprising a horizontal electrode pad and a second floatingITO island, wherein the vertical electrode pad is separated from thehorizontal electrode pad by a plan-view electrode gap, wherein adimension of the first floating ITO island is less than or equal to theplan-view electrode gap, wherein the first transparent electrodecomprises a first laser ablation line between the first floating ITOisland and a third floating ITO island of the first transparentelectrode, wherein the third floating ITO island is most proximate tothe first floating ITO island; and wherein the second transparentelectrode comprises a second laser ablation line between the secondfloating ITO island and a fourth floating ITO island of the secondtransparent electrode, wherein the fourth floating ITO island is mostproximate to the second floating ITO island.
 2. The PCAP touchscreen ofclaim 1, wherein the first laser ablation line and the second laserablation line are centered within the plan-view electrode gap.
 3. ThePCAP touchscreen of claim 1, wherein the first laser ablation line isnot aligned with the second laser ablation line within the plan-viewelectrode gap.
 4. The PCAP touchscreen of claim 1, wherein the firstfloating ITO island is smaller than one or more floating ITO islands ofthe first transparent electrode.
 5. The PCAP touchscreen of claim 4,wherein the one or more floating ITO islands of the first transparentelectrode vary in length.
 6. The PCAP touchscreen of claim 4, whereinthe one or more floating ITO islands of the first transparent electrodeare substantially equivalent in length.
 7. The PCAP touchscreen of claim1, wherein the dimension of the first floating ITO island is based on avarying ITO dicing pattern, the PCAP touchscreen further comprising: afirst signal path from the vertical electrode pad to the horizontalelectrode pad via the first floating ITO island, wherein the firstsignal path comprises at least one high-impedance edge-to-edgecapacitance or one high-impedance small-area capacitance, wherein thefirst signal path has a lower impedance than a fifth signal path fromthe vertical electrode pad to the horizontal electrode pad via a fifthfloating ITO island of the first transparent electrode, wherein thefifth floating ITO island is based on a uniform ITO dicing pattern. 8.The PCAP touchscreen of claim 7, wherein the varying ITO dicing patterncauses a reduction in a value of mutual capacitance, CM, between thevertical electrode pad and the horizontal electrode pad.
 9. The PCAPtouchscreen of claim 7, wherein the varying ITO dicing pattern causes areduction in an RC settling time of the PCAP touchscreen and an increasein touch sensitivity, ΔC_(M)/C_(M).
 10. The PCAP touchscreen of claim 1,wherein a combination of the dimension of the first floating ITO islandand a dimension of the third floating ITO island is less than or equalto the plan-view electrode gap.
 11. The PCAP touchscreen of claim 10,wherein the dimensions of the first and third floating ITO islands areequal.
 12. A method for fabricating a projected capacitive (PCAP)touchscreen, comprising: disposing on a first layer, a first transparentelectrode comprising a vertical electrode pad; disposing on a secondlayer, a second transparent electrode parallel to the first transparentelectrode, comprising a horizontal electrode pad, wherein the verticalelectrode pad is separated from the horizontal electrode pad by aplan-view electrode gap; and creating via laser ablation, a firstfloating indium-tin-oxide (ITO) island and a third floating ITO islandon the first transparent electrode, wherein a dimension of the firstfloating ITO island is less than or equal to the plan-view electrodegap, wherein the third floating ITO island is most proximate to thefirst floating ITO island; and creating via laser ablation, a secondfloating ITO island and a fourth floating ITO island on the secondtransparent electrode, wherein the fourth floating ITO island is mostproximate to the second floating ITO island.
 13. The method forfabricating the PCAP touchscreen of claim 12, wherein a first laserablation line between the first and third floating ITO islands and asecond laser ablation line between the second and fourth floating ITOislands are centered within the plan-view electrode gap.
 14. The methodfor fabricating the PCAP touchscreen of claim 12, wherein a first laserablation line between the first and third floating ITO islands is notaligned with a second laser ablation line between the second and fourthfloating ITO islands within the plan-view electrode gap.
 15. The methodfor fabricating the PCAP touchscreen of claim 12, wherein the firstfloating ITO island is smaller than one or more floating ITO islands ofthe first transparent electrode.
 16. The method for fabricating the PCAPtouchscreen of claim 15, wherein the one or more floating ITO islands ofthe first transparent electrode vary in length.
 17. The method forfabricating the PCAP touchscreen of claim 15, wherein the one or morefloating ITO islands of the first transparent electrode aresubstantially equivalent in length.
 18. The method for fabricating thePCAP touchscreen of claim 12, wherein the dimension of the firstfloating ITO island is based on a varying ITO dicing pattern, the methodfurther comprising: creating a first signal path from the verticalelectrode pad to the horizontal electrode pad via the first floating ITOisland, wherein the first signal path comprises at least onehigh-impedance edge-to-edge capacitance or one high-impedance small-areacapacitance, wherein the first signal path has a lower impedance than asecond path from the vertical electrode pad to the horizontal electrodepad via a fifth floating ITO island of the first transparent electrode,wherein the fifth floating ITO island is based on a uniform ITO dicingpattern.
 19. The method for fabricating the PCAP touchscreen of claim18, wherein the varying ITO dicing pattern causes a reduction in a valueof mutual capacitance, CM, between the vertical electrode pad and thehorizontal electrode pad.
 20. The method for fabricating the PCAPtouchscreen of claim 18, wherein the varying ITO dicing pattern causes areduction in an RC settling time of the PCAP touchscreen and an increasein touch sensitivity, ΔC_(M)/C_(M).